A medical device can be implanted in a body to perform one or more tasks including monitoring, detecting, or sensing physiological information in or otherwise associated with the body, diagnosing a physiological condition or disease, treating or providing a therapy for a physiological condition or disease, or restoring or otherwise altering the function of an organ or a tissue. Examples of an implantable medical device can include a cardiac rhythm management device, such as a pacemaker, a cardiac resynchronization therapy device, a cardioverter or defibrillator, a neurological stimulator, a neuromuscular stimulator, or a drug delivery system.
In various examples, cardiac rhythm or function management devices can sense intrinsic heart contractions, deliver pacing pulses to evoke responsive heart contractions, or deliver a shock to interrupt certain arrhythmias. In certain examples, one or more of these functions can help improve a patient's heart rhythm or can help coordinate a spatial nature of a heart contraction, either of which can improve cardiac output of blood.
Some cardiac rhythm or function management devices can be configured to deliver energy at or near the right ventricle of a patient's heart to achieve pacing via natural conduction pathways, such as when a patient has right bundle branch block. Various methods for treating patients with right bundle branch block have been proposed. For example, Corbucci. U.S. Pat. No. 8,041,424, entitled CARDIAC RESYNCHRONIZATION THERAPY FOR PATIENTS WITH RIGHT BUNDLE BRANCH BLOCK, refers to an implantable medical device and associated method to deliver cardiac resynchronization therapy in a patient having right bundle branch block by measuring an interval between a right atrial depolarization and a first heart sound and selecting a right atrial-ventricular (AV) pacing interval in response to the measure interval.
Zhang et al. U.S. Patent Application No. 20120296228 entitled HEART SOUNDS-BASED PACING OPTIMIZATION, refers to an implantable medical device configured to receive both heart sound and electrogram signals.